docs: def fetch(self, is_dl_forced=False):
          """
          :param is_dl_forced:
          :return:
          """
          self.get_files(is_dl_forced)
  
          ncbi = NCBIGene(self.graph_type, self.are_bnodes_skized)
          # ncbi.fetch()
          gene_group = ncbi.files['gene_group']
          self.fetch_from_url(
              gene_group['url'], '/'.join((ncbi.rawdir, gene_group['file'])), False)
  
          # load and tag a list of OMIM IDs with types
          # side effect of populating omim replaced
          self.omim_type = self.find_omim_type()
  
          return